CD11b+CD28-CD4+ human T cells: activation requirements and association with HLA-DR alleles

Engagement of CD28 induces a major costimulatory pathway required by many CD4+ T cells in addition to activation via the TCR. In the absence of signals provided by CD28, ligation of the TCR alone can induce anergy or apoptosis in CD28+ cells. However, we report here characterization of a distinct subset of CD4+ T cells that are CD28-. Three autoreactive CD4+ human T cell clones that could be activated to produce IL-2 and proliferate by anti-CD3 alone were found to lack expression of CD28. CD28- clones that were activated with anti-CD3 alone were not anergic to restimulation via CD3. The presence of CD28-CD4+ T cells was verified in peripheral blood, and their frequency ranged from 0% to >22% of CD4+ T cells in different individuals. The percentage of CD28-CD4+ T cells in the peripheral blood of 57 individuals was significantly correlated with specific class II MHC alleles. Persons with HLA-DRB1*0401 and DR1 alleles had significantly higher numbers of CD28- T cells, while individuals with HLA-DR2(15) had significantly fewer CD28-CD4+ T cells than the mean. Like the CD28- clones, CD28-CD4+ T cells isolated from peripheral blood proliferated upon CD3 cross-linking in the absence of costimulation. The finding that CD28-CD4+ T cells resist induction of anergy following engagement of the TCR in the absence of conventional costimulation demonstrates one mechanism by which autoreactive T cells can escape processes that censor self-reactivity. The MHC associations observed suggest a relationship with autoimmunity and loss of self-tolerance.     

Effect of lipid transfer proteins on lipoprotein lipase induced transformation of VLDL and HDL

Patients with acute myelocytic leukemia (AML) have varied outlooks for survival after the diagnosis. To identify pretreatment prognostic indicators in AML, we analyzed 132 cases of AML seen at our hospital between June, 1989 and December, 1994. The median age of the patients was 40 years (range, 15-81). There were 63 male and 69 female patients. One hundred eight patients (82%) received induction chemotherapy which was based on cytarabine plus anthracyclines. Sixty six patients achieved complete remission (CR) and the CR rate among the patients given induction chemotherapy was 61%. The median duration of CR was 11.2 months. After median follow up of 6.6 months (range 0.5-51.4), 26 patients (39%) remain in continuous CR. The median duration of overall survival of the patients was 6.7 months. After median follow up of 10.6 months (range, 0.1-52.7), 41 patients (31%) are alive. Variables affecting duration of CR included the age of the patients, performance status of the patients, percentage of blast in the peripheral blood, hemoglobin level, percentage of blast in the bone marrow, FAB subtype, and CD7 marker positivity. Variables affecting survival duration included age of the patients, performance status of the patients, absolute blast count (ABC) in the peripheral blood, bone marrow cellularity, the percentage of blast in the bone marrow, and CD5 marker positivity. Multivariate analysis showed that the age of the patients and percentage of blast in the bone marrow were significant independent indicators for overall survival of the patients. Further studies utilizing cytogenetics and molecular characteristics of leukemic cell are warranted to better define the prognostic factors of patients with AML.     

Percutaneous placement of self-expanding stent for acute traumatic arterial injury

The effect of host strain ploidy on the production of hepatitis B surface antigen (HBsAg) in Saccharomyces cerevisiae was evaluated at the pilot scale (75 L). We found that the accumulation of HBsAg normalized to cell protein was 2-fold higher for the diploid strain compared to its isogenic haploid. No detectable differences in many fermentation parameters were observed (e.g., rate of fermentation, growth rate, final cell yield). However, the enhancement of productivity in the diploid strain appeared to be associated with a slower rate of plasmid shedding (2 microns element) and, thus, a higher average copy number (2-fold at stationary phase) compared to those of the haploid strain.     

Functional results of percutaneous laser discectomy

The purpose of the study was to evaluate laser disc decompression with the KTP 532 laser, used in conjunction with a percutaneous technique, in contained, small to moderately sized lumbar disc herniation. Sixty-three patients who had a contained herniated nucleus pulposus (HNP) and underwent percutaneous laser disc decompression were prospectively studied. Sixty-one were available for follow-up. Access to the disc space was attained with an 18-gauge probe, followed by dilating cannulas guided with an image intensifier. Discography was not performed. The power was set at 10 W, and laser pulses were delivered for 0.2 seconds, with an interval of 0.5 seconds. A total of 1250 J was delivered to the disc space. The average follow-up was 31.75 months (range, 20 to 45 months). Overall, 44 patients (72%) achieved relief of radicular pain, and 33 patients (54%) achieved relief of low back pain. Thirty-six of 61 patients (59%) returned to work by postoperative week 4. Fourteen patients failed treatment, experiencing persistent symptoms (with scores on the Andrews and Lavyne rating scale of < or = 3). In this study group, optimal results were obtained when symptoms were treated within 1 year of presentation. Results from a historical control group are provided for comparison.     

Estrogen receptor-immunoreactive neurons are present in the female rat lumbosacral spinal cord

We investigated the prevalence of quality of care deficiencies in 4,324 Medicare-reimbursed episodes of care provided by 47 home health agencies. The quality of care protocol consisted of a process-oriented, systematic record review by a trained nurse reviewer. Results suggest that an estimated 14.4% of home health care episodes had quality deficiencies with the potential for or actual adverse effects on the patient. Multivariate analyses revealed that the complexity of patients' needs increased the likelihood and severity of the quality problems. Agency ownership was not related to risk of a quality problem, but regional variation in agency effects was observed. Specific problem areas were identified that suggested several ways that home health care could be improved.     

MRI-derived ventricular volume curves for the assessment of left ventricular function

To assess the utility of double oblique, ECG-gated 1H magnetic resonance (MR) derived volume curves for assessing LV function, cardiac short axis images were acquired with a fast field echo technique. We applied this methodology to assess left ventricular function in three groups: normals, patients with left ventricular hypertrophy, and dilated cardiomyopathy. Six slices with 16-20 phases per RR interval were analyzed, representing the initial 75-80% of the cardiac cycle. For each slice, the endocardial border of the left ventricular (LV) chamber was manually traced. Using Simpson's rule, the total LV volume at a given phase was determined considering the traced area, thickness and position in three-dimensional space of each of the six constituent slices. The calculated volumes were plotted against time and the stroke volume, ejection fraction and cardiac output were determined. The volume vs time plots for the systolic and diastolic portions of the curve were individually fit to third degree polynomials using a least squares approximation. From the fit curves, the following data were extracted: the mean slope (dV/dT) during filling and emptying, and the time to 1/4, 1/3 and 1/2 filling and emptying. These parameters are valuable indices of the functional status of the myocardium; thus, accurate and useful estimates of LV function can be obtained using MRI derived volume curves in normal and abnormal states.     

A mass spectrometric solution to the address problem of combinatorial libraries

The molecular weights of femtomole quantities of small peptides attached to polystyrene beads have been determined with imaging time-of-flight secondary ion mass spectrometry. The analysis is made possible by the selective clipping of the bond linking the peptide to a bead with trifluoroacetic acid vapor before the secondary ion mass spectrometry assay. The approach can be applied to large numbers of 30- to 60-micrometer polystyrene beads for the direct characterization of massive combinatorial libraries.     

Role of vacuolar adenosine triphosphatase in the regulation of cytosolic pH in hepatocytes

The almost exclusive media focus on political violence in South Africa has deflected attention from the high levels of interpersonal violence in areas of socioeconomic deprivation. In order to explore the tension between an at-risk community's perspective and the current reality of violence against women, imaginary constructions of their own violent death produced by 45 African female interview respondents were examined in conjunction with forensic data relating to 73 African female homicide victims in Cape Town, South Africa. The prototypical account of an imagined homicide involved a female commuter being approached by a group of men, taunted and assaulted, raped and then killed. The majority of actual homicides occurred at or in the vicinity of the residence of the victim, with the attacker being known to the deceased. Whilst only 1 of the imagined homicide narratives depicted the use of alcohol by the victim, over half the actual homicides had elevated postmortem blood alcohol levels. These and other disjunctions and convergencies between lay and forensic constructions of violent female death should be viewed in the wider context of enmeshment in social circumstance, and could provide some understanding of how at-risk communities perceive violence against women, thereby providing a foundation for appropriate prevention programmes.